1. Field of the Invention
The present invention relates to a solid-state imaging apparatus, an imaging system, and a driving method of the imaging apparatus.
2. Description of the Related Art
Solid-state imaging apparatuses are used as image sensors for digital still cameras and digital video camcorders. Functions required of such imaging systems include an electronic zoom function which selectively reads only part of an imaging region and thereby zooms in or out on an image.
In the solid-state imaging apparatus, electric charges accumulated in photoelectric converting units of the pixels are discharged when signals are read from pixels. However, in the case of pixels from which signals are not read (hereinafter referred to as non-read out pixels), since the electric charges accumulated in the photoelectric converting units are not discharged, electric charges in excess of saturation charge capacity of the photoelectric converting units may overflow from the photoelectric converting units. The electric charges overflowing from the photoelectric converting unit will leak to adjacent pixels via a semiconductor substrate and may produce pseudo signals in pixels from which signals are read (hereinafter referred to as read out pixels). This phenomenon is known as blooming. To address this concern, Japanese Patent Application Laid-Open No. 2005-184358 proposes to reset non-read out pixels during a communications period or frame read out period in the case of a trim scan.